The present method relates, in general, to methods for generating accurate maps and, more particularly, to methods and apparatus for generating road lane maps.
Coarse maps, in either printed or digitally displayed form, show a road as a single line or as two narrowly spaced lines. The width of the line or the space between spaced lines, as the case may be, may be proportional to the actual width of the road. However, such maps do not show the number of lanes in the road or additional exit lanes, bicycle lanes, etc.
Fully automated driving systems are designed to operate a vehicle on a road without driver interaction or other external control, for example, in self-driving or autonomous vehicles. Such systems require maps that encode lane level information at high degrees of precision. The lane level information is used in a variety of situations, such as for generating smooth trajectory for path planning, to predict the behavior of other vehicles, or for planning and reasoning proper vehicle behavior at intersections.
In many cases, such maps are generated either through a tedious manual annotation process, by driving the exact lane layout with a test vehicle or by analyzing a collection of GPS tracks. These methods require significant amounts of manual work, either through annotation or for collection, and may still result in low accuracy maps unless all lanes are driven or due to changes in the number of lanes, or lack of lane identifications, such as at intersections.
It would be desirable to provide accurate lane level maps with less preparation effort.